Re: [RFC PATCH v2 2/3] sched: Introduce cpus_share_l2c

[Mathieu Desnoyers]

On 8/22/23 03:58, Aaron Lu wrote:
> On Sat, Aug 19, 2023 at 08:31:55AM -0400, Mathieu Desnoyers wrote:
> > +#ifdef TOPOLOGY_CLUSTER_SYSFS
> > +static int cpu_get_l2c_info(int cpu, int *l2c_size, int *l2c_id)
> > +{
> > +	const struct cpumask *cluster_mask = topology_cluster_cpumask(cpu);
> > +
> > +	*l2c_size = cpumask_weight(cluster_mask);
> > +	*l2c_id = cpumask_first(cluster_mask);
> > +	return 0;
> > +}
> > +#else
> > +static int cpu_get_l2c_info(int cpu, int *l2c_size, int *l2c_id)
> > +{
> > +	return -1;
> > +}
> > +#endif
> > +
> >   static void update_top_cache_domain(int cpu)
> >   {
> >   	struct sched_domain_shared *sds = NULL;
> >   	struct sched_domain *sd;
> > -	int id = cpu;
> > -	int size = 1;
> > +	int id = cpu, size = 1, l2c_id, l2c_size;
> >   
> >   	sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES);
> >   	if (sd) {
> > @@ -686,6 +704,14 @@ static void update_top_cache_domain(int cpu)
> >   		sds = sd->shared;
> >   	}
> >   
> > +	if (cpu_get_l2c_info(cpu, &l2c_id, &l2c_size)) {
>
> Should be:  cpu_get_l2c_info(cpu, &l2c_size, &l2c_id)

Good point! Thanks for spotting it. I will fix it in a v3.

Mathieu

> > +		/* Fallback on using LLC. */
> > +		l2c_size = size;
> > +		l2c_id = id;
> > +	}
> > +	per_cpu(sd_l2c_size, cpu) = l2c_size;
> > +	per_cpu(sd_l2c_id, cpu) = l2c_id;
> > +
> >   	rcu_assign_pointer(per_cpu(sd_llc, cpu), sd);
> >   	per_cpu(sd_llc_size, cpu) = size;
> >   	per_cpu(sd_llc_id, cpu) = id;
> > --
> > 2.39.2

--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com